ENJOY HOT & COLING WATER, INTUITIVE INDICATOR LIGHTS - Our water dispenser uses advanced compressor technology, which can quickly heat or cool water at room temperature within a few minutes. You don't need to wait for a microwave to heat water in the winter. It’s great for public places such as hospitals, schools, libraries, homes, offices, etc. The control panel in front of the water dispenser has indicator lights. Red light ON means the hot water is heating, Greenlight ON means that the water is cooling, and yellow light means the water is ready to dispense.